NSF's Pan-American Advanced Studies Institute's School on the Dynamics and Chemistry of the Upper Atmosphere
San Juan, Argentina
The Andes region is an excellent natural laboratory for investigating gravity wave influences on the Upper Mesospheric and Lower Thermospheric (MLT) dynamics: during the summer months the dominant gravity waves result from deep convection arising from severe thunderstorms over the continent to the east. In winter this convective activity is expected to be replaced by strong orographic forcing due to intense prevailing zonal winds blowing eastward from the Pacific Ocean and suddenly encountering the towering Andes mountain range (6000m). This creates large amplitude mountain waves that have been measured well into the stratosphere and most recently penetrate occasionally into the mesosphere (Smith et al., 2009). The instrument suite that comprised the very successful Maui-MALT program was recently re-located to a new Andes Lidar Observatory (ALO) located at Cerro Pachon, Chile (30.2°S 70.7°W) to obtain in-depth seasonal measurements of MLT dynamics over the Andes mountains. As part of the instrument set the Utah State University CEDAR Mesospheric Temperature Mapper (MTM) has operated continuously since August 2009 measuring the near infrared OH(6,2) band and the O2(0,1) Atmospheric band intensity and temperature perturbations. This poster focuses on an analysis of nightly OH temperatures and the observed variability, as well as selected gravity wave events illustrating the high wave activity and its diversity.
Pugmire, Jonathan; Criddle, Neal R.; Taylor, Michael J.; Pautet, Dominique; and Zhao, Yucheng, "First Year Investigation of Gravity Waves and Temperature Variability over the Andes" (2010). NSF's Pan-American Advanced Studies Institute's School on the Dynamics and Chemistry of the Upper Atmosphere. Graduate Student Presentations. Paper 8.